Receiving a cancer diagnosis during hospitalization and associations with care outcomes.

11046 Background: Patients often receive their cancer diagnoses during a hospitalization, but little is known about patients who are diagnosed inpatient versus outpatient. We sought to describe associations between patients diagnosed with cancer in the hospital and their clinical outcomes. Methods: We conducted a retrospective cohort study of adults with cancer admitted from 1/2017-12/2022 to the University of Oklahoma Medical Center. Using the electronic health record, we extracted patient demographics (age, sex, race, area deprivation index [ADI; categorized into quartiles Q1-Q4; Q4=areas of highest deprivation]) and clinical characteristics (cancer type, Charlson Comorbidity Index [CCI]), including those who received their cancer diagnosis during their respective hospital admission. We used regression models to explore associations of inpatient cancer diagnosis with patients’ demographics, clinical characteristics, and clinical outcomes (hospital length of stay [hazard ratio {HR} for time to discharge], time to readmission, and overall survival). Results: Among 20,683 hospitalized patients with cancer (mean age 62.2; 51.5% female, 80.0% White, most common cancer types: gastrointestinal [GI; 19.3%], genitourinary [GU; 13.8%], and gynecologic [GYN; 13.7%]), 36.8% of patients received their cancer diagnosis during hospital admission. We found that Black patients (OR=.81, p<.001) and female patients (OR=.91, p=.007) were less likely to receive an inpatient cancer diagnosis. Compared to those with GU cancers, patients with neuroendocrine (OR=1.72, p<.001), thoracic (OR=1.68, p<.001), hematologic (OR=1.38, p<.001), CNS (OR=1.34, p<.001), and GI (OR=1.23, p=.018) cancers were more likely to receive an inpatient diagnosis whereas patients with breast (OR=.48, p<.001), GYN (OR=.67, p<.001), and head/neck (OR=.84, p=.009) cancers were less likely. Patients residing in higher ADI areas (Q2: OR= 1.18, p=.002; Q3: OR=1.55, p<.001; Q4: OR= 1.55, p<.001) were more likely to receive an inpatient cancer diagnosis compared to Q1. Patients with more comorbidities (CCI 1-2: OR=1.41, p<.001; CCI 3+: OR=1.69, p<.001) were more likely to receive an inpatient cancer diagnosis. For clinical outcomes, those who received an inpatient cancer diagnosis had a longer hospital length of stay (HR=.71, p<.001), higher risk of readmission (HR=1.12, p<.001), and worse overall survival (HR=1.28, p<.001) than patients who were not diagnosed in the respective hospitalization. Conclusions: In this large cohort of hospitalized patients with cancer, we identified factors associated with receiving an inpatient cancer diagnosis and demonstrated that diagnosis during hospitalization correlated with worse clinical outcomes. These findings highlight the importance of developing targeted interventions to enhance care delivery and outcomes for individuals who receive their cancer diagnosis during a hospital admission.